OSPF terminology update: Update to OSPF Terminology
Swaps the master/slave wording in OSPF for Leader/Follower across seven RFCs without changing how the protocol works.
Fox, M., Lindem, A., and A. Retana, "Update to OSPF Terminology", RFC 9454, DOI 10.17487/RFC9454, August 2023, <https://www.rfc-editor.org/info/rfc9454>.
@misc{rfc9454,
series = {Request for Comments},
number = 9454,
howpublished = {RFC 9454},
publisher = {RFC Editor},
doi = {10.17487/RFC9454},
url = {https://www.rfc-editor.org/info/rfc9454},
author = {M. Fox and A. Lindem and A. Retana},
title = {{Update to OSPF Terminology}},
pagetotal = 6,
year = 2023,
month = aug,
} RFC text
Contents
Internet Engineering Task Force (IETF) M. Fox
Request for Comments: 9454 IBM
Updates: 2328, 4222, 4811, 5243, 5340, 5614, A. Lindem
5838 LabN Consulting, L.L.C.
Category: Standards Track A. Retana
ISSN: 2070-1721 Futurewei Technologies, Inc.
August 2023
Update to OSPF Terminology
Abstract
This document updates some OSPF terminology to be in line with
inclusive language used in the industry. The IETF has designated
"Guidance for NIST Staff on Using Inclusive Language in Documentary
Standards" by the US National Institute of Standards and Technology
(NIST) for its inclusive language guidelines. It is intended that
all future OSPF documents use this revised terminology even when they
reference the RFCs updated by this document.
This document updates RFCs 2328, 4222, 4811, 5243, 5340, 5614, and
5838.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9454.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents
1. Introduction
2. Update to RFC 2328
3. Update to RFC 4222
4. Update to RFC 4811
5. Update to RFC 5243
6. Update to RFC 5340
7. Update to RFC 5614
8. Update to RFC 5838
9. IANA Considerations
10. Security Considerations
11. References
11.1. Normative References
11.2. Informative References
Acknowledgements
Authors' Addresses
1. Introduction
This document updates some OSPF terminology to be in line with
inclusive language used in the industry. The IETF has designated
"Guidance for NIST Staff on Using Inclusive Language in Documentary
Standards" by the US National Institute of Standards and Technology
(NIST) [NISTIR8366] for its inclusive language guidelines. It is
intended that all future OSPF documents use this revised terminology
even when they reference the RFCs updated by this document.
This document updates [RFC2328], [RFC4222], [RFC4811], [RFC5243],
[RFC5340], [RFC5614], and [RFC5838].
2. Update to RFC 2328
The base OSPFv2 specification "OSPF Version 2" [RFC2328] defines the
synchronization of databases as two routers forming a "master/slave"
relationship. All instances of these terms are replaced by "Leader/
Follower", respectively.
In the Database Description packet, the "master (MS) bit" is renamed
the "Leader (L) bit".
The operation of OSPFv2 is not modified. The Leader/Follower
terminology and Leader (L) bit definition changes impact the
following sections: "The Synchronization of Databases" (Section 7.2),
"The Neighbor Data Structure" (Section 10), "Neighbor states"
(Section 10.1), "Events causing neighbor state changes"
(Section 10.2), "The Neighbor state machine" (Section 10.3),
"Receiving Database Description Packets" (Section 10.6), "Sending
Database Description Packets" (Section 10.8), "An Example"
(Section 10.10), and "The Database Description packet"
(Appendix A.3.3).
3. Update to RFC 4222
"Prioritized Treatment of Specific OSPF Version 2 Packets and
Congestion Avoidance" [RFC4222] is a Best Current Practice (BCP)
document. In Appendix C, Item (2), there is an example OSFPv2 packet
sequence that refers to the "slave" in a database exchange; this
reference is renamed to "Follower".
4. Update to RFC 4811
"OSPF Out-of-Band Link State Database (LSDB) Resynchronization"
[RFC4811] is an Informational document. Section 2.4 includes a
Database Description packet (Figure 2) and a description of the
attendant encoding changes for Out-of-Band Resynchronization. In the
figure and the description, all instances of "MS" (when referring to
the Database Description packet bit) are renamed to "L". There is
also a reference to "Master" in this section that is renamed to
"Leader".
5. Update to RFC 5243
"OSPF Database Exchange Summary List Optimization" [RFC5243] is an
Informational document. The Introduction (Section 1) references
"Master or Slave"; this is replaced by "Leader or Follower".
Section 3 includes an example of the optimized database exchange. In
this example, all instances of "Master" and "Slave" are renamed to
"Leader" and "Follower", respectively.
6. Update to RFC 5340
The base OSPFv3 specification "OSPF for IPv6" [RFC5340] defines the
Database Description process between two routers as one being
"designated to be the master and the other is the slave". All
instances of these terms are replaced by "Leader/Follower",
respectively.
In the Database Description packet, the "Master/Slave (MS) bit" is
renamed the "Leader (L) bit".
The operation of OSPFv3 is not modified. The Leader/Follower
terminology and Leader (L) bit definition changes impact "The
Database Description Packet" (Appendix A.3.3).
7. Update to RFC 5614
"Mobile Ad Hoc Network (MANET) Extension of OSPF Using Connected
Dominating Set (CDS) Flooding" [RFC5614] is an Experimental document.
"Changes to the Neighbor State Machine" (Section 7.1) contains
modifications to the neighbor state machine that were updated from
[RFC2328]. In the neighbor state machine modifications, all
instances of "Master" and "Slave" are renamed to "Leader" and
"Follower", respectively. Additionally, all instances of "MS" (when
referring to the Database Description packet bit) are renamed to "L".
And in "Receiving Database Description Packets" (Section 7.5),
"master or slave" is replaced by "Leader or Follower" in the
parenthetical.
8. Update to RFC 5838
"Support of Address Families in OSPFv3" [RFC5838] is a Standards
Track document. "Database Description Maximum Transmission Unit
(MTU) Specification for Non-IPv6 AFs" (Section 2.7) contains a
Database Description packet change figure that includes the MS bit.
In this figure, the "MS" field is renamed the "L" field.
Additionally, in the first paragraph of "Changes to the Hello Packet
Processing" (Section 2.4), the text is updated to remove the non-
inclusive terms pertaining to unreachability handling as follows:
| When an OSPFv3 router does not support this specification and an
| interface is configured with the Instance ID corresponding to an
| IPv4 AF, packets could be routed toward this interface and
| dropped. This could happen due to misconfiguration or a router
| software downgrade. For example, an IPv4 packet could be received
| on an interface not supporting IPv4 since a router that doesn't
| support this specification can still include the interface in an
| SPF-calculated path as long as it establishes adjacencies using
| the Instance ID corresponding to the IPv4 AF. Note that OSPFv3
| Router-LSAs and Network-LSAs are AF-agnostic.
9. IANA Considerations
In the "Database Description (DD) Packet Flags" registry, IANA has
updated the description for value 0x01 to "Leader (L-bit)" and has
added this document as a reference, as shown below.
Value: 0x01
Description: Leader (L-bit)
Reference: [RFC2328] [RFC9454]
10. Security Considerations
This document updates the terminology used in OSPF RFCs without any
modification to the specifications of the protocol. As such, the
security characteristics of OSPF do not change.
11. References
11.1. Normative References
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC4222] Choudhury, G., Ed., "Prioritized Treatment of Specific
OSPF Version 2 Packets and Congestion Avoidance", BCP 112,
RFC 4222, DOI 10.17487/RFC4222, October 2005,
<https://www.rfc-editor.org/info/rfc4222>.
[RFC4811] Nguyen, L., Roy, A., and A. Zinin, "OSPF Out-of-Band Link
State Database (LSDB) Resynchronization", RFC 4811,
DOI 10.17487/RFC4811, March 2007,
<https://www.rfc-editor.org/info/rfc4811>.
[RFC5243] Ogier, R., "OSPF Database Exchange Summary List
Optimization", RFC 5243, DOI 10.17487/RFC5243, May 2008,
<https://www.rfc-editor.org/info/rfc5243>.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<https://www.rfc-editor.org/info/rfc5340>.
[RFC5614] Ogier, R. and P. Spagnolo, "Mobile Ad Hoc Network (MANET)
Extension of OSPF Using Connected Dominating Set (CDS)
Flooding", RFC 5614, DOI 10.17487/RFC5614, August 2009,
<https://www.rfc-editor.org/info/rfc5614>.
[RFC5838] Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and
R. Aggarwal, "Support of Address Families in OSPFv3",
RFC 5838, DOI 10.17487/RFC5838, April 2010,
<https://www.rfc-editor.org/info/rfc5838>.
11.2. Informative References
[NISTIR8366]
National Institute of Standards and Technology (NIST),
"Guidance for NIST Staff on Using Inclusive Language in
Documentary Standards", NIST Interagency/Internal Report
(NISTIR) 8366, April 2021,
<https://doi.org/10.6028/NIST.IR.8366>.
Acknowledgements
Thanks to Dhruv Dhody, Adrian Farrel, Erik Kline, and Barry Leiba for
their reviews and comments.
Authors' Addresses
Mike Fox
IBM
3039 E Cornwallis Rd.
Research Triangle Park, NC 27709
United States of America
Email: mjfox@us.ibm.com
Acee Lindem
LabN Consulting, L.L.C.
301 Midenhall Way
Cary, NC 27513
United States of America
Email: acee.ietf@gmail.com
Alvaro Retana
Futurewei Technologies, Inc.
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Email: aretana@futurewei.com
ISO Plain Language
On this page
§1Why the Terms Changed
This document updates OSPF terminology to match the inclusive language used in the industry. The IETF has designated the US National Institute of Standards and Technology document "Guidance for NIST Staff on Using Inclusive Language in Documentary Standards", NISTIR 8366, as its inclusive language guideline.
It is intended that all future OSPF documents use the revised terminology, even when they reference the RFCs this document updates. The seven documents updated are RFC 2328, RFC 4222, RFC 4811, RFC 5243, RFC 5340, RFC 5614 and RFC 5838.
The IETF has adopted guidance on inclusive wording for its standards and applied it to the OSPF documents. This note lists which words change and in which books, so that everyone uses the same new words from now on.
§2Leader and Follower in OSPFv2
The base OSPFv2 specification, RFC 2328, defines the synchronization of databases as two routers forming a master and slave relationship. All instances of these terms are replaced by Leader and Follower. In the Database Description packet, the master (MS) bit is renamed the Leader (L) bit.
The RFC states that the operation of OSPFv2 is not modified. The change reaches nine places in RFC 2328: "The Synchronization of Databases" in Section 7.2, "The Neighbor Data Structure" in Section 10, "Neighbor states" in Section 10.1, "Events causing neighbor state changes" in Section 10.2, "The Neighbor state machine" in Section 10.3, "Receiving Database Description Packets" in Section 10.6, "Sending Database Description Packets" in Section 10.8, "An Example" in Section 10.10, and "The Database Description packet" in Appendix A.3.3.
The same treatment is given to OSPFv3 in RFC 5340. That document defines the Database Description process between two routers as one being designated to be the master and the other the slave, and all instances of the terms are replaced by Leader and Follower. Its Master/Slave (MS) bit is renamed the Leader (L) bit. Here too the operation is unchanged, and the change reaches only "The Database Description Packet" in Appendix A.3.3.
When two routers compare their copies of the link-state database, one of them leads the exchange and the other follows. The names for those roles, and the name of the packet bit that marks the leading router, are what change. Every step of the exchange stays exactly as it was.
| Old term | New term |
|---|---|
| master | Leader |
| slave | Follower |
| master (MS) bit | Leader (L) bit |
| Master/Slave (MS) bit | Leader (L) bit |
§3The Other Documents That Change
Five more RFCs get smaller edits.
- RFC 4222, a Best Current Practice document on prioritised treatment of OSPFv2 packets: in Appendix C, item 2, an example OSPFv2 packet sequence refers to the "slave" in a database exchange, and that reference becomes "Follower".
- RFC 4811, Informational, on out-of-band link-state database resynchronization: in Section 2.4, which has a Database Description packet figure and a description of the encoding changes, every "MS" that refers to the packet bit becomes "L", and the reference to "Master" becomes "Leader".
- RFC 5243, Informational, on database exchange summary list optimization: the Introduction, which refers to "Master or Slave", now refers to "Leader or Follower", and every instance of "Master" and "Slave" in the Section 3 example is renamed.
- RFC 5614, Experimental, on a mobile ad hoc network extension of OSPF: in "Changes to the Neighbor State Machine" in Section 7.1, every "Master" and "Slave" becomes "Leader" and "Follower", and every "MS" that refers to the packet bit becomes "L". In "Receiving Database Description Packets" in Section 7.5, the parenthetical "master or slave" becomes "Leader or Follower".
- RFC 5838, a Standards Track document on address families in OSPFv3: the Database Description packet figure in Section 2.7 has its "MS" field renamed to "L".
RFC 5838 also gets one rewritten paragraph. In the first paragraph of "Changes to the Hello Packet Processing" in Section 2.4, the text about a router that does not support the specification is rewritten so that it no longer uses the non-inclusive terms that referred to unreachability handling. The rewritten text explains that packets could be routed toward an interface and dropped because of misconfiguration or a software downgrade, and that a router which does not support the specification can still include such an interface in an SPF-calculated path as long as it establishes adjacencies using the Instance ID for the IPv4 address family, noting that OSPFv3 Router-LSAs and Network-LSAs are address-family agnostic.
Other OSPF documents mention the same old words in examples, diagrams and one longer explanation. Each one gets a list of the sentences to reword, and one paragraph in RFC 5838 is rewritten in full.
- RFC 2328OSPFv2 base specification: nine sections and one appendix.
- RFC 5340OSPFv3 base specification: the Database Description packet appendix.
- RFC 4222Best Current Practice: one packet-sequence example in Appendix C.
- RFC 4811Informational: a packet figure and its description in Section 2.4.
- RFC 5243Informational: the Introduction and a Section 3 example.
- RFC 5614Experimental: the neighbor state machine and a Section 7.5 parenthetical.
- RFC 5838Standards Track: a packet figure in Section 2.7 and a rewritten paragraph in Section 2.4.
§9The IANA Registry Update
IANA updated the "Database Description (DD) Packet Flags" registry. The description for value 0x01 is now "Leader (L-bit)", and the references are RFC 2328 and RFC 9454.
The flag keeps the same value and the same bit position. Only its name and description change, which matches the RFC's statement that protocol behaviour is untouched.
The official list of flag names got the new label, but the flag still sits in the same slot and does the same job.
- 0x01Leader (L-bit) — The flag that marks the leading router in a database exchange.
§10Security Considerations
The RFC states that it updates terminology in OSPF RFCs without any modification to the specifications of the protocol. As a result, the security characteristics of OSPF do not change.
Implementers do not need to alter message processing, only the names used in documentation and, where applicable, in the registry entry.
Because only the names changed, nothing about how safe OSPF is has changed either.